This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: Dyslexia is a developmental condition that affects much as 17% of children (Shaywitz, 1994). In examining the neurobiology of dyslexia, voxel-based morphometry (VBM) studies have shown reduced gray matter density and volume in the left parieto-temporal and left occipito-temporal regions of dyslexic readers when compared to normal readers (Brown et al., 2001;M. A. Eckert et al., 2005;Silani et al., 2005). Specific Aims: Using VBM, this longitudinal study will extend upon previous studies by examining the structural correlates of reading development in adolescent dyslexic readers. Methods: Twenty two adolescents with dyslexia were followed up for 2.5 years. Participants'IQ and word identification (WID) abilities were tested at baseline and follow-up. High resolution anatomical scans were collected at baseline for optimized and modulated VBM analysis. Whole brain regression analyses between local gray and white matter volumes and delta standard scores (ss) were performed, while regressing out baseline age, IQ and WID scores as nuisance variables.